Tasker Reservations

A vovtasker may be reserved for one or more:

• Users
• FairShare groups
• OS groups
• Jobclasses
• Job projects
• Jobs
• Buckets

A tasker can have multiple reservations at any time. Jobs that do not match any reservation are not sent to the tasker if the tasker is reserved. For example:

• If the tasker is reserved for a user, only jobs submitted by that user may be dispatched to that tasker.
• If the tasker is reserved for a group, only jobs from that group may be dispatched to that tasker.
• If the tasker is reserved for a user and a group, only jobs submitted by that user who belongs to that group may be dispatched to that tasker.

Taskers may also be reserved for a negated set, in order to prevent access to the tasker by jobs that match members of the set. To negate a tasker reservation, simply place a not symbol "!" at the beginning of the reservation expression. For example, the command vovtaskermgr reserve -user '!john,mary' -duration 1h tasker1 will allow the tasker named tasker1 to run jobs from any user except john and mary for 1 hour. Any valid reservation expression can be negated.

If a tasker is renamed, the corresponding reservations get updated too. So, the reservations do not get lost.

Reservation rules

Only reservations with end time later than the current time are valid.

There can be multiple reservations on a vovtasker. But there is only one active reservation. If there is already an active reservation, a new reservation overlapping time with the active reservation can be created but ignored. When the active reservation expires (end time passes current time), a new active reservation with earliest start time is picked.

Reservation only applies to normal (direct) taskers or BPS agents. Making reservations on indirect taskers is not allowed.

Duplicate reservations

A new reservation can be created if the reservation is different from existing reservations. Two reservations are the same if the following attributes of reservations are the same. All of these attributes can be specified when creating a reservation using vtk_reservation_create. If a reservation is created through vovtaskermgr, vtk_tasker_reserve, and taskers.tcl, start time and end time are not used as identifiers. The existing reservation with the same other attributes are updated with the new start time and end time. If there is no existing reservation, a new reservation is created.

type

Always tasker if the reservation is for tasker.

what

List of tasker names that this reservation is reserving

start time

Reservation start time

end time

Reservation end time

user

Reservation is for these users

group

Reservation is for these groups

osgroup

Reservation is for these osgroups

jobclass

Reservation is for these jobclasses

jobproj

Reservation is for these jobprojects

bucketid

Reservation is for these bucket IDs

id

Reservation is for these job IDs

The syntax is:

% vovtaskermgr reserve [options] <taskers_list> 

where the options could be:

-user

Comma separated list of users

-group

Comma separated list of groups

-jobproj

Comma separated list of job projects

-jobclass

Comma separated list of job classes

-osgroup

Comma separated list of OS groups

bucketid

Comma separated list of bucket IDs

-id

Comma separated list of job IDs

-start

Start time

-end

End time

-cancel

<tasker_list>

List of tasker names to reserve.

For example, the following command reserves taskers jupiter and alpaca for user john for 3 hours starting from now.

% vovtaskermgr reserve -user john -duration 3h jupiter alpaca

With -cancel option, all reservations on the specified tasker(s) will be removed.

% vovtaskermgr reserve -cancel jupiter alpaca

The following command shows all reservations for taskers.

% vovtaskermgr reserveshow

Examples:

vtk_tasker_define jupitar -reserve "USER john,mary JOBCLASS spectre"
vtk_tasker_define alpaca -reserve "JOBPROJ chipa,chipb DUR 3w"

With Tcl, you can use vtk_tasker_reserve. The syntax is:

vtk_tasker_reserve taskerId [-user <user1,user2,...>]
                          [-group <group1,group2,...>] 
                          [-osgroup <osgroup1,osgroup2,...>]
                          [-jobclass <jobclass1,jobclass2,...>]
                          [-jobproj <jobproj1,jobproj2,...>]
                          [-bucketid <bucketid1,bucketid2,...>]
                          [-id <jobid1,jobid2,...>]
                          [-start <starttime>]
                          [-end <endtime>]
                          [-duration <reserved_duration>]

For example, the following line will clear (cancel) all reservations on tasker 00001230, if there is one. Otherwise, this doesn't have any effect.

vtk_tasker_reserve 00001230

The following line reserves tasker 00001230 for user john for 3 hours starting from now.

vtk_tasker_reserve 00001230 -user john -duration 3h

This reserves tasker 00001230 for user john in group alpha for 2 weeks starting from one hour from now.

vtk_tasker_reserve 00001230 -user john  -group alpha  -start [clock scan "1 hour"]  -duration 2w

The syntax is:

vtk_reservation_create <type> <what> <quantity> <start_time> <end_time> [options]

where:

<what>

Comma separated list of tasker names

<quantity>

Not used for tasker reservations

<start_time>

Reservation start time

<end_time>

Reservation end time

And the options could be:

-user

Comma separated list of users

-group

Comma separated list of groups

-osgroup

Comma separated list of OS groups

-jobclass

Comma separated list of jobclasses

bucketid

Comma separated list of bucket IDs

-id

Comma separated list of job IDs

-update

For example, the following Tcl script creates a reservation for host1 and host2. It reserves 4 slots of each host. It returns ID for the reservation. The ID can be used to update and delete the reservation.

set now [clock seconds]
vtk_reservation_create tasker host1,host2 1 $now [expr $now+3600] -user brian

With -update option, it looks for a reservation which has same attributes except start_time and end_time but the reservation period is overlapping. If there is one, the existing reservation is updated with start_time and end_time.

set now [clock seconds]
set end [expr $now+3600]
set end2 [expr $now+7200]
vtk_reservation_create tasker localhost 1 $now $end -user john #creates a new reservation
vtk_reservation_create tasker localhost 1 $now $end -user john #returns "nochange"
vtk_reservation_create tasker localhost 1 $now $end -group g1  #creates a new reservation
vtk_reservation_create tasker localhost 1 $now $end2 -user john -update #updates the first

To show all existing reservations, use:

% vovshow -reservations

To forget all reservations, use:

% vovforget -allreservations
% vovforget <reservationId>

Reservations data is accessible with vovselect as well.

% vovselect id,reserveuser,reservestart,reserveend from reservations

vtk_reservation_get <reservationId> <variable> provides the details about a reservation.

vtk_reservation_get 21673 info
parray info

Prints out the following information:

info(id)              = 21673
info(quantity)        = 1
info(reservebucketid) = 
info(reservecreated)  = 1513026518
info(reservedby)      = jin
info(reserveend)      = 1513199318
info(reservegroup)    = 
info(reserveid)       = 
info(reservejobclass) = 
info(reservejobproj)  = 
info(reserveosgroup)  = 
info(reservestart)    = 1513026518
info(reserveuser)     = jin
info(type)            = tasker
info(what)            = local2

vtk_reservation_update <reservationId> <fieldname> <new_value> updates a field of reservation with a new value. Available field names can be found by vovselect fieldname from reservations on the command line.

vtk_reservation_update 21673 RESERVEUSER robert

vtk_reservation_delete <reservationId> removes the reservation.

vtk_reservation_delete 21673